A combined full flow and bypass device for treating a fluid substance by filtration and/or addition of one or more chemical additives

Abstract: A combined full flow and bypass oil filter for internal combustion engines includes a generally cylindrical filter body and a generally cylindrical filter head which is threadedly attached to the filter body. The filter head includes an inlet and an outlet and the flow path between the inlet and outlet extends through the filter body. Disposed within the filter body is a generally cylindrical and hollow full flow filtering element and a generally cylindrical and hollow bypass filtering element. The incoming flow of lubricating oil passes through the outer diameter surfaces of the full flow and bypass filtering elements and exits from these filtering elements through their hollow interiors. Concentrically positioned in the exiting flow path of the full flow filter is a Venturi nozzle which creates a low pressure zone. An outlet flow conduit is disposed in flow cooperation with the exiting oil flow through the bypass filtering element and the exit opening of this flow conduit extending from the bypass filtering element is positioned within the low pressure zone of the Venturi nozzle. The pressure differential across the two filtering elements creates a forced flow through the bypass filtering element and the filtered oil through both elements combines as part of a single flow loop.

Description: The present invention relates generally to fluid treatment devices for example for internal combustion engines, gasoline and diesel, and related equipment which require fluid filtration or other fluid treatment. More particularly the present invention pertains to lubricating oil filtration employing both full flow filtration and bypass filtration. Internal combustion engines generally employ two types of filtration in order to clean the lubricating oil. These two types of filtration are commonly referred to as full flow filtration and bypass filtration. Full flow filtering elements receive and filter (relatively coarsely) 90-100% of the regulated oil pump output prior to supplying the oil to the engine components. Bypass filters typically receive only 5-10% of the pump output and are generally effective to "superclean" the oil. Most modern engines (gasoline and diesel) employ full flow filters. Heavy duty engines (particularly diesel) are often equipped with bypass filters in addition to full flow filters. Historically, engineers achieve combined full flow and bypass filtration by one of three methods. One method of creating combined full flow and bypass filtration is to place the full flow and bypass filtering elements in separate containers and provide separate, individual flow circuits with a positive means of forcing flow through the bypass filter. A second method of achieving combined full flow and bypass filtration is to place the full flow and bypass filtering elements in the same container with separate, individual flow circuits and with a positive means of forcing flow through the bypass filter. A third method involved placing the full flow and bypass filtering elements in the same, single container with a single flow circuit through both elements. Treatment devices according to the pre-characterising part of claim 1 are known, for example, from EP-A-0287527, US-A-2843268 and US-A-4655914 which shows the use of a coned Venturi or similar nozzle to increase flow velocity and create a low-pressure zone, outflow from the bypass element being directed to open into said zone to induce flow through that element. In these known constructions the bypass element is in immediate proximity to the nozzle and the full flow element is more remote therefrom so that the part of the flow circuit through the latter is longer and the flow passing through the bypass element enters the low-pressure zone through outlets in the wall of the nozzle so that said flow has to overcome the existing wall forces. The object of the invention is to provide a filter or other fluid treatment device for effecting full flow and bypass treatment in combination which is particularly effective in use, inexpensive in construction, and efficient in operation. The invention provides a combined full flow and bypass device for filtering or filtering and chemically treating a fluid substance, the device having the features defined by the characterising part of claim 1. Preferably the efficient use of the nozzle is increased by positioning the exit opening of the outlet conduit of the bypass element directly in the centre of the main flow through the nozzle. Due to the before mentioned wall forces, the velocity is at its greatest in the centre of the flow therefore the pressure is at its lowest. This allows the maximum use of the velocity profile. Additionally, inserting the exit opening into the centre of the flow allows for greater cross sectional area than possible when outletting through the wall of the nozzle. The increased area allows for greater flow through the bypass filtering element. Although the present invention is detailed and described by reference to oil filtration for an internal combustion engine, it should be stressed that the teachings of the present invention are applicable to virtually any type of fluid, including air. Further, the bypass filtering element disclosed herein may alternatively be a chemically treated element which introduces beneficial chemicals into the oil or other fluid. Examples of the invention are now more particularly described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view in full section of a combined full flow and bypass oil filter according to a typical embodiment of the present invention. FIG. 2 is a side elevational view in full section of the filter body of the FIG. 1 oil filter. FIG. 3 is a side elevational view in full section of the filter head of the FIG. 1 oil filter. FIG. 4 is a side elevational view in full section of a combined full flow and bypass oil filter according to a typical embodiment of the present invention. FIG. 5 is a side elevational view in full section of the filter head of the FIG. 4 oil filter. FIG. 6 is a side elevational view in full section of the filter body of the FIG. 4 oil filter. FIG. 7 is a side elevational view in full section of a combined full flow and bypass oil filter according to a typical embodiment of the present invention. FIG. 8 is a side elevational view in full section of the filter head of the FIG. 7 oil filter. FIG. 9 is a side elevational view in full section of the filter body of the FIG. 7 oil filter. FIG. 10 is a side elevational view in full section of a combined full flow and bypass oil filter according to a typical embodiment of the present invention. FIG. 11 is a side elevational view in full section of a filter head suitable for use with the FIG. 2 filter body according to the present invention. FIG. 11A is a bottom plan view of the FIG. 11 filter head. FIG. 12 is a front elevational view in full section of a combined full flow and bypass oil filter according to a typical embodiment of the present invention. FIG. 13 is a side elevational view in full section of an alternative filter head design according to the present invention. FIG. 13A is a bottom plan view of the FIG. 13 filter head. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. Referring to FIG. 1 there is illustrated as a front elevational view in full section a combined full flow and bypass oil filter 20. Oil filter 20 includes a generally cylindrical filter head 21, a generally cylindrical filter body 22, full flow filtering element 23 and bypass filtering element 24. Each filtering element is generally cylindrical and hollow and each has an outside diameter inlet side and an inside diameter outlet side. The bypass filtering element 24 is in flow and cooperation with an outlet conduit 25 which extends upwardly and concentrically into nozzle 26. Nozzle 26 has a generally cylindrical outer wall surface and an interior shape which includes a narrow throat 29. The bypass filtering element 24 is designed such that all exiting flow through its generally cylindrical open center 24a is directed into outlet conduit 25. While there are four primary Bernoulli obstruction-type nozzle designs, the Venturi nozzle type has been used in styling the interior shape of nozzle 26. The other three primary types include (a) thin-plate orifice, (b) long radius nozzle and (c) the Dall nozzle. Oil flow enters via internally threaded inlet aperture 30 and the oil is allowed to encircle the exterior of filtering elements 23 and 24 via the series radially spaced, circular openings 31 in top plate 32 and via outer clearance regions 33 and 34. The oil which flows through filtering element 23 passes into the inner cylindrical void 35 defined by the inner cylindrical wall 36 of filtering element 23. The exiting flow of this filtered oil passes entirely through nozzle 26 and from there through internally threaded outlet aperture 37. As illustrated in FIG. 1, the narrow throat 29 of nozzle 26 is axially (radially) symmetrical and concentric relative to nozzle 26. Nozzle 26 is concentric with generally cylindrical filtering elements 23 and 24, filter head 21, filter body 22 and outlet conduit 25 which are likewise generally concentric to each other. The upper open end 40 of outlet conduit 25 is positioned within the narrow throat 29 of nozzle 26 coincident with the location of the smallest inside diameter. Nozzle 26 utilizes the full flow of oil via filtering element 23 to create both a high speed flow area and a low pressure zone. The open end 40 of outlet conduit 25 is placed in the low pressure zone. The two filtering elements 23 and 24 share the common inlet aperture 30 resulting in a common upstream pressure zone. However, due to the placement of the outlet conduit 25 in the narrow throat 29, the bypass filtering element 24 has a lower downstream pressure than that of the full flow filtering element 23. The pressure differential across filtering element 24 is greater than that across filtering element 23 causing more oil flow to be drawn through the bypass filtering element 24 than what would otherwise exist for similar filters which do not have the nozzle design of the present invention. The desired flow rate of oil through bypass filtering element 24 can be varied and controlled by the design and dimensions of the nozzle 26, narrow throat 29 and outlet conduit 25. In the FIG. 1 design the nozzle 26 is an integrally assembled part of the filter head 21. The bypass filtering element outlet conduit 25 is placed in the filter body and after assembly of the filter head to the filter body, the outlet conduit 25 is positioned in the narrow throat of the nozzle. Although the outlet conduit 25 and nozzle 26 are separate components in the FIG. 1 illustration, they are specifically designed as a working unit to ensure optimum performance. While the bypass filtering element 24 has been described as an actual filtering element, it is envisioned that it may alternatively be structured as a source of supply for a treatment chemical. While the fluid to be treated would still in all likelihood pass through or over this chemically-treated element, it would treat the fluid more by the addition of one or more chemical additives and less by actual mechanical filtering. It should also be understood that the fluid passing through filter 20, whether oil or some other fluid, is "treated" whether being filtered to remove dirt and contaminants or by adding one or more chemical additives, or both. FIG. 2 illustrates details of the FIG. 1 filter body 22 without the filter head 21. The FIG. 1 filter head 21 is likewise separately illustrated in FIG. 3. Internally threaded sleeve 41 in filter body 22 is designed and arranged to receive by threaded engagement the externally threaded sleeve 42 in filter head 21. As this assembly is completed annular seal 43 fits snugly up into annular channel 44. Referring to FIG. 4 another dual filtering element oil filter 45 according to the present invention is illustrated. While this oil filter operates and performs in a manner which is virtually identical to oil filter 20, there is one primary difference. In the FIG. 4 design the nozzle 46 is incorporated as part of the filter body and the full flow filtering element 47 rather than being part of the filter head 48. The critical differences in upstream and downstream pressures across the two filtering elements is maintained by the fixed positioning of the open end 49 of the outlet conduit 50 relative to the nozzle throat 51. FIG. 5 details the design of the filter head 48 as a separate component from the remainder of filter 45. FIG. 6 details a design of the filter body 52 as a separate component from the filter head 48. The filter head 48 and filter body 52 are assembled by the threaded engagement of sleeve 52a in the filter body with sleeve 48a in the filter head. Annular seal 52b fits snugly up into annular channel 48b. Referring to FIG. 7 another oil filter 55 according to the present invention is illustrated. In the FIG. 7 design a portion 56 of the nozzle 57 is built into the filter body 58 arid a mating portion 59 is built into the filter head 60. The relative positions of the bypass outlet conduit 61 and nozzle throat 62 are or become fixed with the threaded engagement assembly of the filter head 60 onto the filter body 58. The FIG. 7 filter assembly operates and performs in a manner which is virtually identical to that of oil filter 45 as well as to that of oil filter 20. The filter head 60 is separately illustrated in FIG. 8 and the filter body 58 is separately illustrated in FIG. 9. In FIG. 9 an internally threaded, central aperture 63 is disposed concentrically to and directly above nozzle portion 56. In FIG. 8 an externally threaded sleeve 64 surrounds and receives mating nozzle portion 59. Sleeve 64 arid nozzle portion 59 may be cast as a single, integral unit. It is the threaded engagement of sleeve 64 and aperture 63 that completes and creates nozzle 57 and completes the assembly of oil filter 55. Referring now to FIG. 10 there is illustrated an oil filter 70 the design of which is based primarily on the filter head and filter body design of FIG. 4 with the exception that the nozzle design is different. In FIG. 10 the nozzle 71 fits atop the full flow filtering element 72, within and as a part of filter body 73. Nozzle 71 extends downwardly into the hollow, generally cylindrical interior 74 of element 72 and is arranged so as to be concentric therewith. Nozzle 71 includes a reduced diameter throat 75 and the lower most portion (inlet) 76 of the nozzle includes an integral centering device 77. Centering device 77 as incorporated in the nozzle inlet 76 receives the bypass outlet conduit 78. This conduit 78 fits up into aperture 79 formed in shelf portion 80. The centering device 77 controls the concentric centering and longitudinal positioning of the outlet conduit in the low pressure zone of the nozzle 71. Referring to FIG. 11 another head design 85 according to the present invention is illustrated. Head 85 including centering device 87 may be used in conjunction with the FIG. 2 oil filter body wherein the centering device 87 (aperture 88 and shelf portion 89) is added to the inlet of the nozzle. FIG. 11A is a bottom plan view of the FIG. 11 filter head 85, illustrating the structural details of centering device 87. A further variation to what is illustrated in FIG. 10 as now illustrated in FIG. 12 is to remove the centering device 77 and make the bypass outlet conduit 90 an integral extension of nozzle 91 in oil filter 92. By combining the bypass outlet conduit 90 and nozzle 91 as a single, integral component part, optimal location of the outlet 93 of conduit 90 and the low pressure zone 94 of the nozzle is ensured. This particular design also reduces the number of components and simplifies the design and assembly of oil filter 92. This specific arrangement may be used with the filter head and filter body configurations of FIGS. 4, 7, and 10. Another option for the structures of FIGS. 4, 7, 10 and 12 is to configure the nozzle, such as 91 in FIG. 12 and in particular its radial flange (95 in FIG. 12) so as to create fluid-tight sealed surfaces at the interfaces between the nutplate (96 in FIG. 12) and the endplate (97 in FIG. 12) of the full flow filtering element 98. The function of this sealing is to prevent the passage of oil from the inlet to the outlet of the oil filter 92 without first going through the filtering media of filter 92. The advantage of incorporating the required seal as part of the nozzle is the elimination of a separate sealing component. A still further variation to the integral bypass outlet conduit of FIG. 12 is to make this conduit a permanent and integral part of the filter head as illustrated in FIG.13. In FIG.13 filter head 100 includes nozzle 101 and bypass conduit 102 which is an integral part of the nozzle. FIG.13A is a bottom plan view of the FIG.13 filter head 97.

Claims: A combined full flow and bypass device (20) for treating a fluid substance by filtration and/or addition of one or more chemical additives, said device comprising: a body (22); a head (21) assembled to said body and having a flow inlet (30) and a flow outlet (37) wherein the assembled combination of said head and said body defines a flow path from said flow inlet to said flow outlet through said body; a full flow fluid filtering element (23) disposed in said body and positioned within said flow path; a bypass fluid filtering or chemically treated element (24) disposed in said body, positioned within said flow path, and including an outlet flow conduit (25) having an exit opening (40); and a flow nozzle (26) positioned in said flow path and arranged relative to the full flow element and the bypass element such that fluid flow passing through said elements to said flow outlet passes through said flow nozzle; said flow nozzle being shaped to create a low pressure zone therein, and said exit opening being positioned in said low pressure zone; characterised in that the full flow element is positioned in the body immediately adjacent to the flow nozzle and the bypass element is positioned in the body remote from said nozzle with the outlet flow conduit extending along the full flow element to reach the low pressure zone in the nozzle. A device as in claim 1 characterised in that said full flow and said bypass elements (23,24) are both filtering elements. A device as in claim 1 or 2 characterised in that said full flow and said bypass elements (23, 24) are both oil filtering elements. A device as in claim 1 characterised in that the full flow element (23) is a filtering element and the bypass element (24) is a chemically treated element. A device as in any preceding claim characterised in that the nozzle (26) is a Venturi nozzle. A device as in any preceding claim characterised in that the flow nozzle (26) includes integrally therewith a sealing flange (95) designed to prevent fluid flow between the flow inlet (30) and the flow outlet (37) without passing through the full flow element (23). A device as in any preceding claim characterised in that the full flow and bypass elements (23,24) are each generally cylindrical elements having an outer diameter inlet side and an inner diameter outlet side; the outlet flow conduit (25) being disposed in flow co-operation with the outlet side of the bypass element to receive and direct fluid flow operatively exiting therefrom; and the flow nozzle (26) being generally centred relative to the outlet side of the full flow element. A device as in claim 7 characterised in that the outlet flow conduit (25) is in generally an axial relationship within the inner diameter outlet side of the full flow element (23) and the exit opening (40) is substantially centred in the low pressure zone of the nozzle (26). A device as in claim 8 characterised in that the said flow nozzle (71) includes a centring device (77) for the outlet flow conduit (78). A device as in any one of claims 1 to 8 characterised in that the flow nozzle (91) and the outlet flow conduit (90) are created as a single integral member. A device as in any preceding claim characterised in that the flow nozzle (46) is part of said body (52). A device as in any one of claims 1 to 10 characterised in that the flow nozzle (26) is part of said head (21). A device as in any one of claims 1 to 12 characterised in that the flow nozzle (26; 46; 71; 91; 101) is a unitary member. A device as in any one of claim 1 to 10 characterised in that the flow nozzle (57) is configured in two portions, one portion (59) being part of the head (60) and the other portion (56) being part of the body (58). A device as in any one of claims 1 to 11 characterised in that the flow nozzle (71) extends axially into an hollow interior of the full flow filtering element (72) in concentric relationship so that an inlet portion (76) and reduced diameter throat (75) of the nozzle are located within the hollow interior. A device as in any one of claims 1 to 11 characterised in that the flow nozzle (91) extends axially into an hollow interior of the full flow filtering element (98) in concentric relationship so that the low pressure zone (94) of the nozzle is located within the hollow interior.

Inventors: HEDGECOUGH SARGEON BILLY, JIANG ZEMIN, LANIUS MIKE B, LOFTIS TED S, MOTLOW ERIKA B, SUITER DWIGHT S, HEDGECOUGH, SARGEON BILLY, JIANG, ZEMIN, LANIUS, MIKE B., LOFTIS, TED S., MOTLOW, ERIKA B., SUITER, DWIGHT S.
Applicants: FLEETGUARD INC, FLEETGUARD, INC.
Application year: 1994
Main classification: B01D29
IPC codes: B01D35, F16N39, F01M11, F01P5, B01D27, F01M1